Jack head for flat knitting machines



Dec. 25, 1951 A. J. COBERT JACK HEAD FOR FLAT KNITTING MA CHINES Filed Aug. 11, 1950 JNVENTOR. ARTHUR q. COBERT ZQIMM ATTORNEY Patented Dec. 25, 1951 UNITED STATES PATENT OFFICE 2,579,649 JACK HEAD FOR FLAT KNITTINGMAGHINEQ Arthur J. Cobert, Chattanooga, Tenn., assignor of one-half to Bryan F. F. Mills, 1m, Chattanooga, Tenn., a corporation v Application August 11, 1950, Serial No. 178,881

, 15 Claims.

This invention relates to jack heads for full fashioned flat knitting machines, and more particularly to an improved striking jack and jack spring. The invention also concerns the means by which the .jack springs are controlled.

In the ordinary fiat knitting machines, small pivoted fingers called striking jacks are mounted in a row on a carrier bar and are actuated by a slur cam to force the face of the jack against a sinker to cause the sinker to move forward in the formation of the stitch until it contacts the verge plate which is adjustable to determine the depth to which the sinkers go, and it is customary to use springs in cooperation with either thesinkers Or the associated striking jacks to prevent rebound in order to preserve uniformity of the stitches.

Previously, springs have been arranged to press against an elongated heel of the striking jack, or arranged to press into a notch formed in the sinker. In both of these prior art arrangements, the pressure required of the slur cam to move the sinker forward is substantially as great as the holding pressure of the spring against rebound; however, with my novel spring and striking jack arrangement, the spring slips easily into a notch provided on the forward edge of the jack when the jack is pushed forward, but the holding power of this spring against rebound is much greater because the spring is not put under compression, as in the prior art devices, but is almost astraight wire which holds by tension. Because very little pressure is required to force my striking 'ack forward against the pressure of my novel spring, very little wear is had with my novel construction as compared with prior art devices where relatively great pressure was required to move the striking jacks forward against the spring pressure which was necessarily large in order to have sufiicient spring pressure available toprevent rebound.

An object of my invention is to provide an improved jack head assembly for full fashioned flat knitting machines.

Another object of my invention is to provide a jack head assembly in which strong holding power is had against rebound, but relatively very little pressure is required to move the jacks forward.

Another object of my invention is to provide a jack head assembly in which the operation causes but little wear on the parts thereof.

Another object of my invention is to provide an improved striking jack.

animproved jack spring.

Mother Object or "my invention is to "provide 2 a Jack spring constructed to be moved to op'e'i' ative engagement by compression and to hold against rebound by tension.

Another object of my invention i to provide a jack head having an improved jack spring bar and operating mechanism. l I

Other and further objects and advantages of my invention will be apparent from the following description taken in connection with the accompanying drawing in which like characters of reference designate corresponding parts throughout the several views, and wherein:

Fig. 1 is a perspective view of a striking jack made in accordance with my invention.

Fig. 2 is an end view ofa jack head, showing jack spring bar assembled to it, according to my invention.

Fig. 3 is a detail view of a spring member used in connection with my striking jack.

Fig. 4 is a broken, partially disassembled view of the Jack head assembly, showing the strkiing jack in retracted position. V v

Fig. 5 is a view similar to that of Fig. 4 and showing the striking jack in forward position where the same is held by the spring member. The figure further shows, in broken lines, the movement of the jack spring and jack spring bar to permit the striking jack to be returned to the retractedposition.

In the embodiment chosen for purpose of illustration, the striking jacks in are rotatably supported in the usual way by their carrier bar ii and are held in place by retainer bar l2 beneath which they roll. Thesejacks are provided with a face l3 and rounded heel M of known design, and are also provided in their forward edges with the novel. slot or indentation l5 for cooperation with my jack spring [6, of novel design, as will be hereinafter more fully pointed out.

The jack springs t6, one of which is provided for each striking jack Hi, are firmly held in a movable jack spring bar I! which is provided with a trumiion i8 projecting from each end thereof for vertical sliding movement in the rectangular bearings 19, one being attached to each end of the jack head bymeans of cap screws 26. Elongated holes 20' are provided 'to permit horizontal adjustmentof the bearings. Reciproeating movement is imparted to the jack spring bar ['1 through the trunnion l8 which is moved up and down in the rectangular bearing [9 by means of the yoke 21 on the end of rocker arm 22 which is pivoted to the jack head at 23 'andto which intermittent motion transferred from the main drive of the knitting machine (not shown). Adjusting screw 2| limits the downward travel of yoke 2| and prevents the spring bar from dropping down too far, which would cause increased pressure on the springs, beyond a desirable point. a l

wardly at an angle of approximately 45 toward.

the striking jacks, then an intermediate section '5 i6 extending nearly straight up, and finally a downwardly turned tip or end section I6 arranged for engagement with the notch IS in the forward edge of a jack l0. On the opposite end of each jack spring is provided a heel or inturned section to aid in securing the spring to the Jack spring bar. In accordance with the usual construction, the Jacks lfl move between pairs of jack walls 24, shown in Figs. 4 and 5, the end plate 24', shown in Fig. 2, having been removed; and the jack springs I6 also move between pairs of jack walls; and the springs are made substantially the same thickness as the jacks so as to prevent them from slipping in between the jack and the jack wall.

In operation, after the sinkers (not shown) and striking jacks are pulled back by the catch bar .(not shown) so that the jacks are in the retracted position shown in Figs. 2 and 4, the yoke 2| moves the jack spring bar [1 downwardly, thus positioning the springs [6 for engagement, respectively, with a notch IS in" the forward edge of a, jack Iii. As each jack is moved forward, the tip end I6 of a spring [6 rides gently up along the forward face of the jack until the tip slides into the slot [5, as shown in Fig. 5, when the jack reaches its forward position. In this position it will be seen that any tendency of the jack to rebound will be resisted by a pull on the spring 16, and that while the spring could easily be flexed slightly outwardly to permit the tip end to drop into the slot I5, a great deal more force would be required to flex the spring under tension to cause a lengthwise expansion, of the almost straight line wire, to release the tip IB from the slot l5. As the motion of the machine progresses, however, the jack spring bar H is raised by the yoke 21 to the position shown in broken lines in Fig. 5, and in this position the jack i0 is free to be moved back to the retracted position without having to overcome tension in the spring it, because the raised position of the bar I! lifts the tip iB .off the bottom of the slot 15, as clearly shown in broken lines in Fig. 5.

It will be obvious that my invention provides a great improvementand advance in the art, and

that while I have illustrated and described my invention in a very practical embodiment thereof, various changes, adaptations and modifications may be made without departing from the scope of my invention as defined in the followin claims.

I claim:

1. A striking jack for a full fashioned knitting machine having a forward edge provided with a striking face, said edge being slotted for the pivotal mounting of said jack, characterized by an additional slot in said forward edge forming a shoulder for engagement with a rebound checking member. 1 V

2. In combination in a jack head for knitting machines, a pivotally mounted striking jack arranged to cause a sinker to move forward in the formation of a stitch, said jack having holding means on its forward edge for engagement with a rebound checking member, and a rebound checking member mounted for selective engagement with said holding means.

3. Incombination in a jack head for knitting machines, a pivotally mounted striking jackarrecess.

4. In combination in a jack head for knitting machines, a pivotally mounted striking jack arranged to cause a sinker to move forward in the formation of a stitch, said jack having holding means on its forward edge for engagement with a rebound checking member, and a. rebound checking member mounted for selective engagement with said holding means, said rebound checking member having a straight section, a section extending at approximately 45 to said straight section, an intermediate section in substantail alignment with said straight section, and an end section arranged for engagement with said holding means.

5. In combination in a jack head for knitting machines, a pivotally mounted striking jack arranged to cause a sinker to move forward in the formation of a stitch, said jack having a recess in its forward edge for reception of a rebound checking member, and a rebound checking member mounted for selective engagement in said re- 'cess, said rebound checking member having an upright section, a central section extendingat an angle of approximately 45 to said upright section, an intermediate section extending nearly vertically, and a downwardly turned end section arranged for engagement in said recess.

In combination in a jack head for knitting machines, a pivotally mounted striking jack arranged to cause a sinker to move forward in the formation of a stitch, said jack having holding means on its forward edge for engagement with a rebound checking member, a carrier bar mounted for movement adjacent said striking jack, a rebound checking member carried by said bar for selective engagement with said holding means, and means for moving said bar, whereby said rebound checking member is moved out of engagement with said holding means.

7. In combination in a jack head for knitting machines, a pivotally mounted striking jack arranged to cause a sinker to move forward in the formation of a stitch, said jack having holding means on its forward edge for engagement with a rebound checking member, a bar mounted for straight line movement adjacent said striking jack, a rebound checking member carried by said bar for selective engagement with said holding means, a bearing supporting said bar, and means for moving said bar in said bearing, wherebysaid rebound checking member is moved out ofengagement with said holding means.

8. In combination in a jack head for knitting machines, a pivotally mounted striking jack arranged to cause a sinker to move' forward in the formation of a stitch, said jack having a recess in its forward edge for reception of a rebound checking member, a bar mounted for straight line movement adjacent said striking jack, 9. rebound checking member carried by said bar for selective engagement in said recess, a bearing supporting said bar, and a yoke carried by a pivoted member for moving said bar in said bearing, whereby said rebound checking member is moved selectively out of engagement with said recess.

9. In combination in a jack head for knitting machines, a pivotally mounted striking Jack arranged to cause a sinker to move forward in the formation of a stitch, said jack having a recess in its forward edge for reception of a rebound checking member, a bar mounted for vertical movement adjacent said striking jack, a rebound checking member carried by said bar for selective engagement in said recess, a rectangular bearing supporting said bar, and a yoke carried by a pivoted member for moving said bar up and down in said bearing, whereby said rebound checking member is moved out of engagement with said recess when bar is moved up.

10. In combination in a jack head for knitting machines, a striking jack pivotally mounted to move forward to cause a sinker to move forward in the formation of a stitch and arranged to be withdrawn to retracted position when desired, said jack having holding means on its forward edge for engagement with a rebound checking member, a rebound checking member mounted for movement adjacent said striking jack, said rebound checking member being arranged for engagement with said holding means as said striking jack is moved forward, said rebound checking member holding said striking jack against rebound when it is in engagement with said holding means, and means to move said rebound checking member to disengage it from said striking jack, whereby said striking jack can be freely withdrawn to retracted position without resistance from said rebound checking member.

ll. In combination in a jack head for knitting machines, a striking jack pivotally mounted to move forward to cause a sinker to move forward in the formation of a stitch and arranged to be withdrawn to retracted position when desired, said jack having holding means on its forward edge for engagement with a rebound checking member, a flexible rebound checking member mounted for straight line movement adjacent said striking jack, said rebound checking member being arranged to flex and ride along the forward edge of said striking jack for engagement with said holding means as said striking jack is moved forward, said rebound checking member holding said striking jack against rebound by tension in said member when it is in engagement with said holding means, and means to move said rebound checking member in a straight line to disengage said rebound checking member from said striking jack, whereby said striking jack can be freely Withdrawn to retracted position without resistance from said rebound checking member.

12. In combination in a jack head for knitting machines, a striking jack pivotally mounted to move forward to cause a sinker to move forward in the formation of a stitch and arranged to be withdrawn to retracted position when desired, said jack having holding means on its forward edge for engagement with a rebound checking member, a bar mounted for straight line movement adjacent said striking jack, a flexible rebound checking member carried by said bar, said rebound checking member being arranged to flex and ride along the forward edge of said striking jack for engagement with said holding means as said striking jack is moved forward, said rebound checking member holding said striking jack against rebound by tension in said member when it is in engagement with said holding means, and means to move said bar in a straight line to disengage said rebound checking member from said striking jack, whereby said striking jack can be freely withdrawn to retracted position without resistance from said rebound checking member. 13. In combination in a jack head for knitting machines, a striking jack pivotally mounted to move forward to cause a sinker to move forward in the formation of a stitch and arranged to be withdrawn to retracted position when desired, said jack having a recess in its forward edge for reception of a rebound checking member, a bar mounted for straight line movement adjacent said striking jack, a flexible rebound checking member carried by said bar, said rebound checking member being arranged to flex and ride along the forward edge of said striking jack for engagement in said recess as said striking jack is moved forward, said rebound checking member holding said striking jack against rebound by tension in said member when it is in engagement with said recess, and means to move said bar in a straight line to disengage said rebound checking member from said striking jack, whereby said striking jack can be freely withdrawn to retracted position without resistance from said rebound checking member.

14. In combination in a jack head for knitting machines, a striking jack pivotally mounted to move forward to cause a sinker to move forward in the formation of a stitch and arranged to be withdrawn to retracted position when desired, said jack having a recess in its forward edge for reception of a rebound checking member, a bar mounted for straight line movement adjacent said striking jack, a flexible rebound checking member carried by said bar, said rebound checking member having a free end arranged to flex and ride along the forward edge of said striking jack for engagement in said recess as said striking jack is moved forward, said rebound checking member holding said striking jack against rebound by tension in said member when it is in engagement with said recess, a bearing supporting said bar, and a yoke arranged to move said bar in a straight line to disengage said free end of said rebound checking member from said striking jack, whereby said striking jack can be freely withdrawn to retracted position without resistance from said rebound checking member.

15. In combination in a jack head for knitting machines, a striking jack pivotally mounted to move forward to cause a sinker to move forward in the formation of a stitch and arranged to be withdrawn to retracted position when desired, said jack having a recess in its forward edge for reception of a rebound checking member, a bar mounted for vertical movement adjacent said striking jack, a rebound checking member carried by said bar, said rebound checking member having a free end arranged to ride along the forward edge of said striking jack for engagement in said recess as said striking jack is moved forward, said rebound checking member holding said striking jack against rebound by tension in said member when it is in engagement with said recess, a rectangular bearing supporting said bar, and a yoke arranged to move said bar in a straight line to disengage said free end of said rebound checking member from said striking jack, whereby said striking jack can be freely withdrawn to retracted position without resistance from said rebound checking member.

ARTHUR J. COBERT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,730,023 Waechtler Oct. 1, 1929 1,830,718 Richter Nov. 3, 1931 2,216,502 Riedel Oct. 1, 1940 

